Restraining migration and dissolution of transition-metal-ions via functionalized separator for Li-rich Mn-based cathode with high-energy-density

Lithium-rich manganese-based materials (LRMs) are promising cathode for high-energy-density lithium-ion batteries due to their high capacity, low toxicity, and low cost. However, LRMs suffer from serious voltage decay and capacity fade due to continual migration and dissolution of transition metal ions (TMs) during cycling process. Herein, a novel strategy is proposed to inhibit the TMs migration of LRMs through a modified separator by means of functionalized carbon coating layer, which depends on the chemical constraint of the abundant functional groups in the modified super P. In addition, it has been found that the dissolution of TMs can be restrained based on the Le Chatelier’s principle. Moreover, the modified separator owns good wettability toward the electrolyte. As a result, the LRMs cathode with the modified separator delivers a high discharge capacity of 329.93 mA h g−1 at 0.1 C, and achieves good cyclic performance, the enhanced reaction kinetics and low voltage decay. Therefore, this work provides a new idea to promote the comprehensive electrochemical performances of Li-ion batteries with LRMs cathode through a strategy of separator modification.